In the 3GPP (3rd Generation Partnership Project), studies relating to Home Node B (for example, a base station used indoors; hereafter called “femtocell”) are being conducted (see for example, 3GPP TR 25.820).
A femtocell registers a useable terminal in advance, the registered terminal can communicate via the femtocell. By using the femtocell, a situation in which the terminal is out of the service area in indoor can be prevented, and the base station can be monopolized by a small number of the terminals so that communication capacity can also be increased. And the terminal can communicate with the femtocell using low transmission power. Moreover, the number of the terminals accessing base station for general use which is installed outdoors (hereafter called “macrocell”) is reduced, so that throughput can be improved for the terminals using such macrocell.
However, although the femtocell is useful, in order for the terminal to detect the femtocell, frequency switching, cell searching, and other processing must be performed frequently, so that power consumption is increased. Also, to the extent that the terminal performs the processing, the time during which the terminal can be used for data reception is reduced, and throughput suffers.
Further, the terminal receives the BCH (Broadcast channel) from all detected femtocells, and extracts the cell IDs of the femtocells, by performing the terminal cell search for the femtocell. However, nearly all of the numerous femtocells are dedicated for use by other terminals, in actuality. Hence, the terminal receives the BCH from femtocell to which the terminal cannot be accessed, and to this extent the terminal power consumption is increased.